All Questions

12 questions with bounties
Filter by
Sorted by
Tagged with
1 vote
98 views
+150

Confusion about the LCAO or tight binding model (nearest neighbors)

I'm using the book "Atomic and Electronic Structure of Solids" by Kaxiras. In chapter 4, the author introduces the tight binding or LCAO model for calculating electronic band structures. He ...
• 1,517
1 vote
154 views
+100

Explaining lift on a wing via forces

Consider the bottom of a wing. Air below the wing is deflected downwards by the wing. Hence by Newton's 3rd Law the wind must exert an equal and opposite force on the wing. Hence lift, and this makes ...
1 vote
230 views
+50

What would be an experimental test of Sciama’s theory and why it has not been pursued yet?

Recently I came across a video were the origin of inertia was attributed to Sciama’s paper (1953). I have seen only a couple of questions regarding this topic on Stack Physics. Both of them are ...
• 289
185 views
+50

Experimental status/test possibilities for baryon number conservation in LHC?

Violation of baryon number is hypothesized e.g. for baryogenesis (more matter than antimatter from Big Bang) or Hawking radiation (baryons -> black hole -> massless radiation) - quite extreme ...
• 980
1 vote
61 views
+50

Asymptotic form of wavefunctions in case of $k$ one-dimensional asymptotic regions

I'm reading the paper Hamiltonian Truncation Study of Supersymmetric Quantum Mechanics, and am struggling to understand some things about section 2. In particular eqn 2.2, and how to think about the ...
• 211
83 views
+50

How does the bulk-to-boundary propagator transform under diffeomorphisms?

In AdS/CFT, the bulk-to-bulk propagator can be obtained as the limit of the bulk-to-bulk propagator with one point approaching the boundary. For example in the scalar case K_{\Delta}(...
1k views
+50

There is a well known experiment to determine the specific charge of an electron like in the following picture Electrons are emitted from a heating spiral and then accelerated by an acceleration ...
• 161
254 views
+50

What is the single active electron approximation?

I keep stumbling upon this approximation while reading papers on atomic physics, but I couldn't find a proper description of what it is in any textbook or pedagogical paper. The closest I could find ...
• 3,953
1 vote
38 views
+50

Reference request scale anomaly

Can anyone recommend some books, notes and review-oriented papers on scale anomaly, with a view towards its relation to renormalization? Such as an anomaly perspective on RG, Callan-Symanzik equations ...
63 views
+100

Limits of outward fission neutron multiplication

Suppose we want a source of a large amount of neutrons for e.g. transmutation. Is it possible to arrange neutron reflectors, absorbers and fissile or fertile material in such a way that the induced ...
92 views
+50

Mathematical explanation of the extinction paradox

I am trying to learn properly about scattering. For this I was pointed to Wave Propagation and Scattering in Random Media by Ishimaru. I got a bit stuck in section 2-2 General properties of the Cross ...
Above are pictures of a problem in mechanics. An elastic body occupying domain $\Omega$ is supported below with a fixed support and from above with a rigid body. The following calculations aim to ...